Following feedback from that discussion, and invaluable input received
at a recent meeting with representatives from major web archives (see http://www.mementoweb.org/events/IA201002/)
, we have made some revisions/rationalizations to the proposed
framework.

(*) Use of a HTTP Link header instead of a HTTP 302 redirect to allow
navigation from an Original Resource to a TimeGate for it. This solves
a caching issue faced by the initial approach, and also allows
applying the framework to non-information resources in order to allow
retrieving their prior descriptions (see the final slides of the
aforementioned slide deck).
(*) Use of the same architecture (distinct Original Resource,
TimeGate, Memento) for scenarios that involve Web archives and Content
Management Systems as servers of Mementos.